The prior art in the field of mobile water-analysis is currently represented by so-called photometric cuvette tests as described in DE 41 09 118 A1. The use of these tests is performed manually. First, a water-sample is taken by a pipette and given into the cuvette. For determining the self-absorption of the water-sample, i.e., the so-called background signal, the water-sample is inserted into the photometer and is measured. A reagent is then added to the water-sample in the cuvette. The cuvette is closed and shaked to mix the water-sample with the key-reagent. It is subsequently inserted into a photometer and measured.
The handling of such a cuvette test is inconvenient and extremely susceptible to errors. The used reagent can be dangerous for health and the environment, so that the used cuvette tests must be disposed in an appropriate way. The inconvenient handling makes the cuvette tests only applicable for use in a laboratory. Such water-sample analyzation, including the determination of the self-absorption of the water-sample, can be performed automatically in a non-mobile water-analyzing system.